Abstract:Low pre-mating weight and/or low weight gain from mating to pregnancy diagnosis was associated with increased fetal loss, emphasising the importance of ewe lambs achieving target pre-mating weights and liveweight gains during pregnancy. Infection with Leptospira serovar Pomona was associated with fetal loss in the 2012-born cohort and the possibility of infection with this serovar should be considered when investigating cases of fetal loss.
“…The presence of antibodies against the serogroup Pomona was previously reported in sheep from slaughterhouses (Caffarena, Cacchione, Cascelli, & Martínez, ) and in cattle (Zarantonelli et al., ) in Uruguay. Furthermore, Pomona serogroup strains have been implicated in clinical disease in lambs in other countries (Davidson & Hirsh, ; Ellis et al., ; Leon‐Vizcaino et al., ; Ridler et al., ; Vermunt et al., ,b). In our study, we isolated for the first time two strains of L. interrogans serogroup Pomona serovar Kennewicki from naturally infected sheep.…”
Section: Discussionmentioning
confidence: 99%
“…serogroups Pomona, Grippotyphosa and Sejroe (serovar Hardjo) were isolated from ovine fetuses, suggesting a possible role of these serogroups in sheep abortion (Ellis, Bryson, Neill, McParland, & Malone, ; Leon‐Vizcaino, Hermoso de Mendoza, & Garrido, ). Fetal losses have also been found to be associated with seroreactivity to serogroup Pomona (Ridler, Vallee, Corner, Kenyon, & Heuer, ).…”
Summary
Acute leptospirosis is an infrequent disease in sheep that can cause jaundice, haemolysis, haemoglobinuria, hepatitis and nephritis. In most reports the diagnoses have been made by clinical, pathological or serological evidence without isolation or direct identification of the agent. Here, we report one confirmed and one presumptive outbreak of acute leptospirosis in suckling lambs from two unrelated sheep farms in Uruguay with mortalities of 9/60 (15%) and 9/163 (5.5%) lambs. Both outbreaks occurred in Sep–Oct 2017 after heavy rainfall and flooding events. The main gross and histologic pathological findings in two autopsied lambs, one from each farm, included severe diffuse jaundice, haemoglobinuria, acute necrotizing hepatitis with cholestasis and interstitial nephritis. Leptospira interrogans serogroup Pomona serovar Kennewicki was isolated from sheep in both flocks and the same genotype was identified directly in clinical samples from infected animals, including one of the deceased lambs subjected to autopsy, by amplification and partial sequencing of rrs and secY genes. This serovar has recently been identified in infected cattle and humans in Uruguay. The impact of Leptospira spp. infection in ovine health, and the epidemiologic role of sheep as reservoirs of leptospirosis for humans and animals need further investigation.
“…The presence of antibodies against the serogroup Pomona was previously reported in sheep from slaughterhouses (Caffarena, Cacchione, Cascelli, & Martínez, ) and in cattle (Zarantonelli et al., ) in Uruguay. Furthermore, Pomona serogroup strains have been implicated in clinical disease in lambs in other countries (Davidson & Hirsh, ; Ellis et al., ; Leon‐Vizcaino et al., ; Ridler et al., ; Vermunt et al., ,b). In our study, we isolated for the first time two strains of L. interrogans serogroup Pomona serovar Kennewicki from naturally infected sheep.…”
Section: Discussionmentioning
confidence: 99%
“…serogroups Pomona, Grippotyphosa and Sejroe (serovar Hardjo) were isolated from ovine fetuses, suggesting a possible role of these serogroups in sheep abortion (Ellis, Bryson, Neill, McParland, & Malone, ; Leon‐Vizcaino, Hermoso de Mendoza, & Garrido, ). Fetal losses have also been found to be associated with seroreactivity to serogroup Pomona (Ridler, Vallee, Corner, Kenyon, & Heuer, ).…”
Summary
Acute leptospirosis is an infrequent disease in sheep that can cause jaundice, haemolysis, haemoglobinuria, hepatitis and nephritis. In most reports the diagnoses have been made by clinical, pathological or serological evidence without isolation or direct identification of the agent. Here, we report one confirmed and one presumptive outbreak of acute leptospirosis in suckling lambs from two unrelated sheep farms in Uruguay with mortalities of 9/60 (15%) and 9/163 (5.5%) lambs. Both outbreaks occurred in Sep–Oct 2017 after heavy rainfall and flooding events. The main gross and histologic pathological findings in two autopsied lambs, one from each farm, included severe diffuse jaundice, haemoglobinuria, acute necrotizing hepatitis with cholestasis and interstitial nephritis. Leptospira interrogans serogroup Pomona serovar Kennewicki was isolated from sheep in both flocks and the same genotype was identified directly in clinical samples from infected animals, including one of the deceased lambs subjected to autopsy, by amplification and partial sequencing of rrs and secY genes. This serovar has recently been identified in infected cattle and humans in Uruguay. The impact of Leptospira spp. infection in ovine health, and the epidemiologic role of sheep as reservoirs of leptospirosis for humans and animals need further investigation.
“…A proportion of 0.75 was used to simulate foetal loss due to Pomona in Pomona seropositive ewes (Ridler et al, ). At the population level, this kind of abortion outbreak due to Pomona was thought to be a rare event.…”
Section: Methodsmentioning
confidence: 99%
“…In New Zealand, seropositivity to Leptospira borgpetersenii serovar Hardjo (Hardjo‐bovis) and Leptospira interrogans serovar Pomona (Pomona) is highly prevalent in beef cattle, sheep and deer (Ayanegui‐Alcerreca et al, ; Dreyfus et al, ). Additionally, foetal loss was associated with Hardjo‐bovis and Pomona seropositivity in beef cattle (Sanhueza, Heuer, & West, ), and Pomona seropositivity in one sheep farm (Ridler, Vallee, Corner, Kenyon, & Heuer, ). Furthermore, vaccination trials in deer suggested an economic benefit of immunization against leptospirosis due to increased growth rate and weaning percentage (Subharat, Wilson, Heuer, & Collins‐Emerson, , ).…”
Background
Human leptospirosis mainly affects people in close occupational contact with domestic livestock and their products in New Zealand. The disease has an unquantified impact on both human health and animal production in the country. This study aimed to estimate the burden of leptospirosis in terms of disability‐adjusted life years (DALYs) and cost associated with loss due to absence from work, treatment of disease, animal production loss and cost of vaccination.
Methods
Previously published studies of abattoir workers farmers, and veterinarians, reporting annual risks of influenza‐like illness attributable to Leptospira infection, were used to estimate the expected number of cases in a year. The cost of lost animal production was based on results of observational studies in beef cattle, sheep and deer conducted in New Zealand.
Results
Expected median annual number of severe and mild cases of human leptospirosis was 2,025 (95% probability interval [95% PI] 1,138–3,422). Median annual DALYs were 0.42 (95% PI: 0.06–2.40) per 100,000 people for the entire population, and 15.82 (95% PI: 2.09–90.80) per 100,000 people working in at‐risk occupations (i.e. abattoir workers, farmers and veterinarians). Human infection resulted in a median cost of 4.42 (95% PI: 2.04–8.62) million US dollars (USD) due to absence from work and disease treatment. Median production loss cost in beef cattle, sheep and deer was USD 7.92 (95% PI: 3.75–15.48) million, while median vaccination cost in cattle, (including dairy), sheep and deer was USD 6.15 (95% PI: 5.30–7.03) million. Total annual cost of leptospirosis plus vaccination was USD 18.80 (95% PI: 13.47–27.15) million, equivalent to USD 440,000 (95% PI: 320,000–640,000) per 100,000 people.
Conclusion
This study provides an estimate of the disease burden and cost of leptospirosis in New Zealand that could support occupational health authorities and livestock industries in assessing interventions for this disease.
“…However, there are several challenges for the maintenance of reproductive efficiency, with handling infectious diseases being key among them. Leptospirosis is a significant zoonotic bacterial disease (ALLAN et al, 2018;COSTA et al, 2015), which has been associated with reproductive failure and economic losses in sheep (RIDLER et al, 2015).…”
Leptospirosis is a zoonosis that is widely distributed in tropical countries. This infection is also associated with reproductive losses in livestock, which has a significant economic impact. The objective of this study is to investigate the seroprevalence and risk factors associated with leptospiral infection in commercial sheep flocks from the northwestern mesoregion of Rio Grande do Sul. Serum samples were analyzed in 319 sheep using the Microscopic Agglutination Test (MAT). At the time of sampling, an individual and herd questionnaire was carried out to investigate the risk factors. On an individual level, positive reactions were observed in 5.6% (18/319) of the studied sera, with Sejroe being the most prevalent serogroup. Animals >3 years old were more likely to be seropositive than animals 1-3 years old (OR 14.4; 95% CI 1.9-110). The predominance of Sejroe serogroup in this manner draws attention to how subclinical infection is associated with economic losses. Therefore, the importance of maintaining measures for the prevention and control of leptospirosis among the sheep flocks of the studied region is reiterated.
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